﻿// 读取随机数
Math.uuid = (function () {
    // Private array of chars to use
    var CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');

    return function (len, radix) {
        var chars = CHARS, uuid = [], rnd = Math.random;
        radix = radix || chars.length;

        if (len) {
            // Compact form
            for (var i = 0; i < len; i++) uuid[i] = chars[0 | rnd() * radix];
        } else {
            // rfc4122, version 4 form
            var ri = 0, r;

            // rfc4122 requires these characters
            uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
            uuid[14] = '4';

            // Fill in random data.  At i==19 set the high bits of clock sequence as
            // per rfc4122, sec. 4.1.5
            for (var i = 0; i < 36; i++) {
                if (!uuid[i]) {
                    r = 0 | rnd() * 16;
                    uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r & 0xf];
                }
            }
        }
        return uuid.join('');
    };
})();



